From 345ec382cd4b736c36e01f155d08c913b225b736 Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Tue, 4 Apr 2023 18:21:24 +0100 Subject: [PATCH] nvmem: core: add per-cell post processing Instead of relying on the name the consumer is using for the cell, like it is done for the nvmem .cell_post_process configuration parameter, provide a per-cell post processing hook. This can then be populated by the NVMEM provider (or the NVMEM layout) when adding the cell. Signed-off-by: Michael Walle Signed-off-by: Miquel Raynal Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-17-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 17 +++++++++++++++++ include/linux/nvmem-provider.h | 3 +++ 2 files changed, 20 insertions(+) --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -54,6 +54,7 @@ struct nvmem_cell_entry { int bytes; int bit_offset; int nbits; + nvmem_cell_post_process_t read_post_process; struct device_node *np; struct nvmem_device *nvmem; struct list_head node; @@ -470,6 +471,7 @@ static int nvmem_cell_info_to_nvmem_cell cell->offset = info->offset; cell->bytes = info->bytes; cell->name = info->name; + cell->read_post_process = info->read_post_process; cell->bit_offset = info->bit_offset; cell->nbits = info->nbits; @@ -1563,6 +1565,13 @@ static int __nvmem_cell_read(struct nvme if (cell->bit_offset || cell->nbits) nvmem_shift_read_buffer_in_place(cell, buf); + if (cell->read_post_process) { + rc = cell->read_post_process(nvmem->priv, id, index, + cell->offset, buf, cell->bytes); + if (rc) + return rc; + } + if (nvmem->cell_post_process) { rc = nvmem->cell_post_process(nvmem->priv, id, index, cell->offset, buf, cell->bytes); @@ -1671,6 +1680,14 @@ static int __nvmem_cell_entry_write(stru (cell->bit_offset == 0 && len != cell->bytes)) return -EINVAL; + /* + * Any cells which have a read_post_process hook are read-only because + * we cannot reverse the operation and it might affect other cells, + * too. + */ + if (cell->read_post_process) + return -EINVAL; + if (cell->bit_offset || cell->nbits) { buf = nvmem_cell_prepare_write_buffer(cell, buf, len); if (IS_ERR(buf)) --- a/include/linux/nvmem-provider.h +++ b/include/linux/nvmem-provider.h @@ -54,6 +54,8 @@ struct nvmem_keepout { * @bit_offset: Bit offset if cell is smaller than a byte. * @nbits: Number of bits. * @np: Optional device_node pointer. + * @read_post_process: Callback for optional post processing of cell data + * on reads. */ struct nvmem_cell_info { const char *name; @@ -62,6 +64,7 @@ struct nvmem_cell_info { unsigned int bit_offset; unsigned int nbits; struct device_node *np; + nvmem_cell_post_process_t read_post_process; }; /**